In a related patent application, Ser. No. 417,473, entitled VEHICLE MOUNTABLE ELECTRICAL GENERATING SYSTEM, filed Sept. 13, 1982, and specifically incorporated herein by reference, the inventor has disclosed electrical generating systems suitable for wheel mounting on automotive vehicles, particularly semi-trailer trucks, to power an associated signal transmitter which is responsive such as to a tire pressure sensor.
The generating systems described in application Ser. No. 417,473 employ a pendulum journaled about the axis of rotation of the wheel on which the assembly is mounted, the pendulum remaining essentially stationary during wheel rotation to provide a mechanically coupled non-rotating reference whereby the armature and magnetic field structure are driven into relative rotation with respect to each other. An integral overspeed gearing system generates a potential in response to wheel rotation, and thus provides power to the transmitter at the lower vehicle speeds.
The wheels of semi-trailers have wheel assemblies wherein the webs of the outer wheels are configured concavely inward, with the axle assembly ends well inboard of the outermost lateral extension of the trailer body, and ample space is available for the generator-transmitter assembly of the aforementioned invention. Thus, the generating systems of the Applicant's related patent application are suitable for mounting axially outwardly of the vehicle axis assembly.
However, the front wheels of the cab or tractor pulling the semi-trailer have wheel webs which typically face convexly outwardly; and the axle assembly ends are disposed somewhat outboard of the tractor body. Devices mounted axially outwardly of the front axle assemblies would project well outboard of the vehicle, possibly being hazardous, would be vulnerable to damage and also may comprise a safety hazard.
The generating system described in U.S. patent application Ser. No. 417,473 and the toroidal-shaped generating system described herein are electrically and mechanically compatible with each other. A desirable condition would be to use the system of the present invention on the convexed front wheels while using the system of said Ser. No. 417,473 on the rear concave wheels of the truck tractor and trailer.